Detection of Gray Hole Attack in Software Defined Networks

Gray Hole Attack is an advanced transformation of black hole attack. Both of them are a common type of attack in Wireless Sensor Network (WSN). Malicious nodes may constantly or randomly drop packets and therefore reduce the efficiency of the networking system. Furthermore Software Define Network (SDN) has been highly developed in recent years. In this type of networks switch/router functionality is separated into the control plane and data plane. Network managers can select control policies and build operating rules according to their own preferences. In addition, network protocols and packet fields are also programmable. Because the switch/router only implements the data transmission and executes the switching/routing decisions based on commends coming from control plane. Compromised switches/routers themselves or malicious control instructions both can result in selectively dropped packets. This makes a gray hole attack possible in the infrastructure of SDN. Therefore, this paper would like to discuss time-base and random-base gray hole attack in SDN, and then propose a useful detection method based on weighted K-Nearest Neighbor (KNN) and Genetic Algorithm (GA). The simulation data collected from switches/routers indicate that our method does demonstrate pretty good performance

Three Taiwanese students' identity transformations: the complexity within the same cohort of international students

Although the complexity of Chinese-speaking international students' (CHISs) identity transformation has been emphasized in previous research, there is a perceived linear and causal pattern between studying abroad and being intercultural. This pattern of thinking results in the risk of treating all the CHISs as the same in each cohort of students. Drawing on Bourdieu's notion of habitus, this auto/ethnographic study followed three Taiwanese international postgraduate students' lives over one year to elucidate the complexity of their identity transformation. The findings suggest a variety of identity changes resulting from the participants’ evaluation of their past, present and future situations

Systemic Associations with Residual Subretinal Fluid after Ranibizumab in Diabetic Macular Edema

Purpose. To investigate the impact of systemic diseases on the occurrence of subretinal fluid (SRF) in diabetic macular edema (DME) and prognostic factors for residual SRF following three consecutive monthly intravitreal ranibizumab. Methods. Ninety-seven eyes from 68 patients with DME who completed 3 consecutive monthly injections of ranibizumab were enrolled. Systemic parameters mainly included chronic kidney disease (CKD), hypertension, HbA1c, and insulin dependence. Renal parameters for CKD were serum creatinine, estimated glomerular filtration rate (eGFR), and serum albumin. Ocular factors were baseline central macular thickness (CMT), severity of diabetic retinopathy (DR), and status of panretinal photocoagulation (PRP). Results. Chronic kidney disease had significant correlation with baseline SRF (R=0.397, p<0.001 after partial correlation with adjustment for age and DR severity). As for CKD, lower serum albumin, but not eGFR or serum creatinine, was associated with baseline presence of SRF (p=0.026, p=0.08 and p=0.53, resp., after adjustment for age and DR severity). Overall, lower eGFR and lower HbA1c values, contrary to popular belief, predicted the presence of residual SRF following intravitreal injections (p=0.016 and p<0.001, resp.). Conclusions. Tight sugar control and poorer baseline kidney function may slow the resorption of SRF after anti-VEGF injections in patients with DME in the short term

Combined Tractional and Rhegmatogenous Retinal Detachment in Proliferative Diabetic Retinopathy in the Anti-VEGF Era

Purpose. To investigate the clinical features, surgical outcomes, and prognostic factors of combined rhegmatogenous and tractional detachment (combined RD) in proliferative diabetic retinopathy (PDR) in recent years. Methods. Medical records of PDR and combined RD treated with vitrectomy from 2008 to 2013 were retrospectively reviewed. Results. A total of 57 eyes from 49 patients were included. Nine eyes had received panretinal photocoagulation (PRP) and 7 eyes had intravitreal bevacizumab (IVB) within 3 months before RD developed. Thirty-eight eyes (66.7%) had ≧3 sites of broad adhesion of fibrovascular proliferation (FVP). Thirty-three eyes (57.9%) showed active FVP. Thirty-four eyes (59.6%) had extent of RD involving 3 or 4 quadrants. The primary reattachment rate was 93.0%, and the final visual acuity (VA) improved by more than 3 lines in 80.7% of eyes. Neovascular glaucoma occurred in 4 eyes postoperatively. Poor preoperative VA, severe vitreoretinal adhesion, and broad extent of RD had significant correlation with poor visual outcomes. Conclusion. PRP or IVB might play a role in provoking combined RD. The anatomical and functional success rates of surgery were high. Poor preoperative VA and severe proliferations predicted poor visual outcomes

Decay Constants of Pseudoscalar DD-mesons in Lattice QCD with Domain-Wall Fermion

We present the first study of the masses and decay constants of the pseudoscalar $D$ mesons in two flavors lattice QCD with domain-wall fermion. The gauge ensembles are generated on the $24^3 \times 48$ lattice with the extent $N_s = 16$ in the fifth dimension, and the plaquette gauge action at $\beta = 6.10$, for three sea-quark masses with corresponding pion masses in the range $260-475$ MeV. We compute the point-to-point quark propagators, and measure the time-correlation functions of the pseudoscalar and vector mesons. The inverse lattice spacing is determined by the Wilson flow, while the strange and the charm quark masses by the masses of the vector mesons $\phi(1020)$ and $J/\psi(3097)$ respectively. Using heavy meson chiral perturbation theory (HMChPT) to extrapolate to the physical pion mass, we obtain $f_D = 202.3(2.2)(2.6)$ MeV and $f_{D_s} = 258.7(1.1)(2.9)$ MeV.Comment: 15 pages, 3 figures. v2: the statistics of ensemble (A) with m_sea = 0.005 has been increased, more details on the systematic error, to appear in Phys. Lett.

Unraveling implicit human behavioral effects on dynamic characteristics of Covid-19 daily infection rates in Taiwan

We study Covid-19 spreading dynamics underlying 84 curves of daily Covid-19 infection rates pertaining to 84 districts belonging to the largest seven cities in Taiwan during her pristine surge period. Our computational developments begin with selecting and extracting 18 features from each smoothed district-specific curve. This step of computing effort allows unstructured data to be converted into structured data, with which we then demonstrate asymmetric growth and decline dynamics among all involved curves. Specifically, based on Theoretical Information measurements of conditional entropy and mutual information, we compute major factors of order-1 and order-2 that reveal significant effects on affecting the curves' peak value and curvature at peak, which are two essential features characterizing all the curves. Further, we investigate and demonstrate major factors determining the geographic and social-economic induced behavioral effects by encoding each of these 84 districts with two binary characteristics: North-vs-South and Unban-vs-suburban. Furthermore, based on this data-driven knowledge on the district scale, we go on to study fine-scale behavioral effects on infectious disease spreading through similarity among 96 age-group-specific curves of daily infection rate within 12 urban districts of Taipei and 12 suburban districts of New Taipei City, which counts for almost one-quarter of the island nation's total population. We conclude that human living, traveling, and working behaviors do implicitly affect the spreading dynamics of Covid-19 across Taiwan profoundly

Information environment and participation of foreign banks in U.S. syndicated loan market

This study examines how financial information quality affects the participation and lending behavior of foreign banks in the loan syndicate of U.S borrowers. We utilize the implementation of the Sarbanes-Oxley Act (SOX) in the U.S. as our research setting. We demonstrate a significant increase in foreign banks loan shares to public firms in the post-SOX period. In parallel, we find that this increase in lending by foreign banks is accompanied by more favorable price and non-price contract terms. By contrast, we find no evidence of either more loans or more favorable loan contract terms offered to U.S. privately held borrowers by foreign banks. Further analysis shows that the impact of such an exogenous change on loan contract terms are more pronounced among public listed borrowers with higher ex ante information asymmetry. Overall, our findings imply that the increase in quality and reliability of corporate financial information brought about by SOX reduces the information disadvantage of foreign lenders

Cryopreservation of Orchid Genetic Resources by Desiccation: A Case Study of Bletilla formosana

Many native orchid populations declined yearly due to economic development and climate change. This resulted in some wild orchids being threatened. In order to maintain the orchid genetic resources, development of proper methods for the long‐term preservation is urgent. Low temperature or dry storage methods for the preservation of orchid genetic resources have been implemented but are not effective in maintaining high viability of certain orchids for long periods. Cryopreservation is one of the most acceptable methods for long‐term conservation of plant germplasm. Orchid seeds and pollens are ideal materials for long‐term preservation (seed banking) in liquid nitrogen (LN) as the seeds and pollens are minute, enabling the storage of many hundreds of thousands of seeds or pollens in a small vial, and as most species germinate readily, making the technique very economical. This article describes cryopreservation of orchid genetic resources by desiccation and a case study of Bletilla formosana. We hope to provide a more practical potential cryopreservation method for future research needs